Piezoelectric ultrasonic wave guide probe for steel rail bottom flaw detection and flaw detection method thereof

Abstract

The invention discloses a piezoelectric ultrasonic wave guide probe for steel rail bottom flaw detection and a flaw detection method thereof. The probe comprises an outer layer casing, a plurality ofpiezoelectric units and at least one interface, wherein each piezoelectric unit comprises a piezoelectric wafer, a cable wire, a damping block, a sound absorption filling material, an elastic elementand an inner layer casing; the piezoelectric wafer is a piezoelectric ceramic piece with the length direction vibration mode and is arranged at the bottom of the outer layer casing; the vibration direction is parallel to the horizontal surface; one side, parallel to the vibration direction and near the inside, of the piezoelectric wafer is tightly attached to the damping block; the damping block is arranged in the inner layer casing; the sound absorption filling material is filled between the damping block and the inner layer casing; the elastic element is arranged between the inner layer casing and the outer layer casing; the connector is arranged on the top of the outer layer casing and is connected with the piezoelectric wafer through the cable wire. The piezoelectric wafer with the length direction vibration mode is used; the sensitivity is high; the single-time detection distance is long; the signal-to-noise ratio is high; the small damage can be inspected out; meanwhile, the costis low; the popularization is convenient.

Description

technical field [0001] The invention relates to a flaw detection device and a flaw detection method thereof, in particular to a piezoelectric ultrasonic guided wave probe and a flaw detection method for rail bottom flaw detection, belonging to the technical field of nondestructive testing. Background technique [0002] Rail flaw detection is one of the key tasks to ensure the safe operation of trains. At present, ultrasonic technology is generally used for rail flaw detection. The ultrasonic probe transmits pulsed sound waves from the rail head tread to the rail and receives its reflected waves to detect damage. Ultrasonic flaw detection technology can only inspect a local area around the probe each time pulsed sound waves are emitted, and there are large flaw detection blind spots on both sides of the rail bottom. Although rail head damage is still the main factor causing rail breakage, the number of rail breakage events or accidents caused by rail bottom damage has also s...

AI Technical Summary

Problems solved by technology

[0005] I Bartoli et al., J Zhang et al., Lu Chao et al. used the hammering method to conduct ultrasonic guided wave flaw detection of rails. However, in the guided wave signal obtained by the hammering method, the modal recognition degree of the guided wave is low, so the guided wave receiving transduction is required. The sensor is close to the damage point, which is often difficult to achieve in actual detection

In addition, the hammering method is not suitable for production practice

[0006] In recent years, non-contact ultrasonic guided wave flaw detection based on laser ultrasonic and air coupling has also made great progress, but there are still obvious defects in signal-to-noise ratio, accuracy, and generalizability.

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